What is the prevalence of visual impairment in the general and diabetic populations: are there ethnic and gender differences?

Aims To estimate the prevalence of blindness and partial sight in the general and diabetic populations and to measure the impact of ethnicity and gender on these rates. Methods Data on visual impairment in the population to be studied was obtained from the Royal Leicestershire Rutland and Wycliffe Society for the Blind (RLRWSB). Using the validated technique of capture‐mark‐recapture (CMR), a census day was set and data from four sources collected: hospital admissions data, GP returns, wards, and mass media. Computer cross‐linkage to Leicestershire Health Authority data ensured patients were alive and resident in Leicestershire at the census date. Estimates of diabetes, ethnicity and gender prevalence were calculated using the 1991 census. Results CMR calculations revealed that there was under ascertainment of visual impairment in the RLRWSB data. The CMR calculations with direct age standardization estimate the prevalence of blindness and partial sight in the general and diabetic populations to be 51.8/10 000 (CI 50.6–53.0) and 148.8/10 000 (CI 122.1–175.5), respectively. In the diabetic population there was a higher proportion of visually impaired females than males (P